Method for in-situ promotion of surface soil humification components in rice field driven by peridome organisms

Abstract

This invention relates to a method for in-situ enhancement of humic components in paddy field surface soil driven by periwinkle organisms. The method includes: crushing rice straw and soaking it in a periwinkle organism culture medium for a predetermined time; drying the soaked rice straw and spreading it on the paddy field surface after rice transplanting; controlling the light conditions on the field surface and implementing periodic short-term drying management during the rice tillering to booting stage. This invention utilizes an adsorbent straw-induced matrix to induce the rapid and directional colonization of periwinkle organisms, an aggregate of indigenous microorganisms at the paddy field soil-water interface, in situ, rather than exogenously adding microorganisms. This method offers high ecological safety and can simultaneously increase the content of humus, total organic carbon, and dissolved organic carbon in the paddy field surface soil within a single rice growing season. The method is simple to operate and suitable for large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of agricultural ecological engineering and soil organic carbon regulation technology, specifically involving a method for in-situ enhancement of humic components in paddy field surface soil driven by periclump organisms. Background Technology

[0002] In paddy field ecosystems, returning straw to the field is an important measure to increase soil organic carbon. However, under long-term flooding conditions, the straw decomposition process is slow, and a large amount of organic carbon exists in soluble or unstable forms, making it difficult to effectively transform into stable humic components, thus limiting the role of soil carbon sink.

[0003] In existing technologies, the following methods are often used to promote the soil humification process: 1) adding artificial carriers containing straw, inorganic fertilizers and microbial agents to paddy fields; 2) applying exogenous humic acid or chemical humification promoters; 3) accelerating the humification reaction through specific water depths or closed reaction environments.

[0004] The aforementioned methods generally suffer from problems such as reliance on external inputs, high costs, poor ecological adaptability, or difficulty in large-scale promotion in paddy fields. Furthermore, they can easily alter the original biological processes in paddy fields, posing potential ecological risks. Therefore, there is an urgent need for a technical method that does not rely on exogenous microbial agents or nutrient carriers, can induce the enrichment and growth of native paddy field microbial aggregates under in-situ conditions, and synergistically promote biological carbon fixation and straw humification, thereby increasing the content of humic components, especially stabilizing the content of humic components such as humic acid (HA) and humin (HM). Summary of the Invention

[0005] The purpose of this invention is to provide a method for in-situ enhancement of humic components in paddy field surface soil driven by periclump organisms. By constructing induction conditions conducive to the in-situ enrichment and growth of periclump organisms, this method induces the in-situ directional enrichment and growth of periclump organisms in the paddy field surface and around straw without introducing exogenous chemical humifying agents, microbial agents, or artificial nutrient carriers. This promotes the rapid depolymerization and humification transformation of straw organic matter mediated by periclump organisms. Simultaneously, it increases the content of humus, total organic carbon, and dissolved organic carbon in the paddy field surface soil, achieving stable accumulation of humic components in the soil.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for in-situ enhancement of humic components in paddy field surface soil driven by periclump organisms, characterized in that the method comprises: After crushing the rice straw, soak it in the Zhou Cong biological culture medium for a preset time. After soaking and drying the rice straw, spread it on the surface of the paddy field after rice transplanting. Adjust the field light conditions and implement periodic short-term drying management during the tillering to booting stage of rice.

[0007] In some embodiments of the present invention, the rice straw is soaked in a periwinkle culture medium for 20-30 hours.

[0008] In some embodiments of the present invention, the pericarp culture medium is a concentrated WC culture medium.

[0009] In some embodiments of the present invention, the soaked rice straw is naturally drained and then spread on the surface of the paddy field.

[0010] In some embodiments of the present invention, the dried rice straw is applied on the same day after rice transplanting.

[0011] In some embodiments of the present invention, light and water level regulation are performed after the application of rice straw and before rice tillering, wherein the water level regulation includes: After spreading rice straw, maintain the first water level and gradually lower the water level to the second water level during the early stage of periclump formation and growth completion; the first water level > the second water level.

[0012] In some embodiments of the present invention, the periodic short-term drying management includes: Maintain the first water level for 23-27 days, then dry it out for 3-7 days; after that, irrigate and maintain the second water level until the heading stage; the first water level > the second water level.

[0013] In some embodiments of the present invention, the first water level is 5-7 cm; the second water level is 3-5 cm.

[0014] In some embodiments of the present invention, the application rate of rice straw is 25-30 kg / mu.

[0015] In some embodiments of the present invention, the soil humification components include humic acid, fulvic acid, and humin.

[0016] The present invention has the following beneficial effects: 1) It induces the rapid and directional colonization of native microbial aggregates around the soil-water interface in paddy fields through in-situ induction, rather than by adding microorganisms from external sources and without using artificial carriers containing nutrients, thus ensuring high ecological safety. 2) By using an adsorbent straw-inducing matrix, a microenvironment conducive to the growth of periclump organisms is constructed on the surface of the straw, which significantly promotes straw degradation; 3) It can simultaneously increase the content of total organic carbon, dissolved organic carbon, humic acid, fulvic acid (FA) and humin in the topsoil of paddy fields within a single rice growing season, thereby enhancing the soil organic carbon content. 4) The method is simple to operate, does not change the conventional rice paddy farming system, and is suitable for large-scale promotion and application. Attached Figure Description

[0017] Figure 1 This is a comparison chart showing the changes in humic acid content in the surface soil of the experimental field (experimental group) and the control field (control group) in the example.

[0018] Figure 2 This is a comparison chart of the changes in fulvic acid content in the surface soil of the experimental field (experimental group) and the control field (control group) in the example.

[0019] Figure 3 This is a comparison chart of the changes in humin content in the topsoil of the experimental field (experimental group) and the control field (control group) in the example.

[0020] Figure 4 This is a comparison chart of the changes in total organic carbon content in the topsoil of the experimental field (experimental group) and the control field (control group) in the examples.

[0021] Figure 5 This is a comparison chart showing the changes in dissolved organic carbon content in the surface soil of the experimental field (experimental group) and the control field (control group) in the examples.

[0022] Figure 6 This example compares the average content of humic acid, fulvic acid, humin, total organic carbon, and dissolved organic carbon in the topsoil of the experimental field (experimental group) and the control field (control group) in multiple samplings. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] The high-concentration peritrichous culture medium described in this example is a culture medium concentrated five times based on the medium designed in the applicant's previous application CN114958819A. Its concentrated components are as follows: The WC culture medium composition is: NaNO3 425.5 mg·L⁻¹ -1 KH2PO4 43.55 mg·L -1 MgSO4·7H2O 184.85 mg·L -1 NaHCO3 63mg·L -1 CaCl2·2H2O 183.8 mg·L -1 NaSiO4·9H2O 142.1 mg·L -1 H3BO3 120mg·L -1 Trace element solution I 1 ml·L -1 VB 12 1 ml·L solution-1 1 ml / L of VB1 solution -1 Biotin solution 1 ml·L -1 ; Composition of trace element solution I: Na₂EDTA·2H₂O 21.8 mg·L⁻¹ -1 FeCl3 15.75 mg·L -1 ZnSO4·7H2O 110mg·L -1 MnCl2·4H2O 900 mg·L -1 CuSO4·5H2O 12.5 mg·L -1 NaMoO4·2H2O 31.5 mg·L -1 Na3VO4 90mg·L -1 ; VB 12 Solution composition: HEPES buffer 60 g·L -1 VB 12 0.675 g·L -1 ; Composition of VB1 solution: HEPES buffer 60 g·L -1 VB 12 1.675 g·L -1 ; Composition of biotin solution: HEPES buffer 60 g·L -1 Biotin 0.125 g·L -1 ; The three vitamin solutions were prepared in 200 mL of HEPES buffer, the pH was adjusted to 7.8, and the solutions were stored at low temperature and protected from light.

[0025] Example 1 In a contiguous paddy field in Baitu Town, Jurong City, Jiangsu Province, the paddy fields were divided into an experimental group (experimental field) where the growth of periclumps was regulated using an inducible straw substrate, and a control group (control field) where the growth of periclumps was not regulated using an inducible straw substrate. Rice seedlings were transplanted on June 18th, and the inducible straw substrate was applied on the same day. From June 25th to August 20th, topsoil samples (0–20 cm) from both the experimental and control fields were collected every 7 days to determine the contents of humic acid, fulvic acid, humin, total organic carbon, and dissolved organic carbon.

[0026] The preparation method of the induced straw substrate is as follows: rice straw is crushed and soaked in a high concentration of cyclohexane culture medium for 24 hours, so that the soluble nutrients in the culture medium are adsorbed and impregnated into the surface and pore structure of the straw. Then it is taken out and drained naturally. The resulting straw maintains a loose and porous structure and is used as the cyclohexane induced straw substrate.

[0027] In the experimental field, on the day after straw transplanting, the aforementioned induced straw substrate was evenly applied to the surface of the paddy field in a thin layer, at a rate of approximately 25-30 kg / mu. The light environment of the field surface was regulated to ensure sufficient sunlight from the greening stage to the pre-tillering stage. Simultaneously, during the tillering to booting stage of the rice, periodic short-term drying management was implemented, using a water rhythm management method of shallow water – short-term drying – then shallow water again to promote the renewal of periclinal organisms and the release of extracellular metabolites.

[0028] The method for regulating the field's light environment is to supplement light using natural or artificial light. Additionally, after spreading rice straw, initially maintain a water layer of 5-7 cm. At this stage, some straw floats on the surface, providing suitable light intensity with adequate shade for the germination of peripheral organisms. As the peripheral organisms form and expand, the water layer can be gradually lowered to 3-5 cm, or the straw can be partially submerged by microorganisms, naturally reducing water surface coverage and thus gradually increasing interfacial light, promoting community maturation. The specific method for dry-land management is as follows: first, irrigate to a depth of 5-7 cm and maintain for about 25 days, then dry-land for about 5 days, and then irrigate again to a depth of 3-5 cm and maintain for 30 days.

[0029] Apart from the additional application of induced straw substrate, the other cultivation conditions, including light and drying management, were the same for the experimental and control fields.

[0030] Example 2: Comparison of changes in active carbon components in soil between experimental and control fields like Figures 1-3 As shown, during the rice growing season, the content of humic acid, fulvic acid, and humin in the soil of both the control field and the experimental field showed an overall fluctuating upward trend.

[0031] Overall, the average values ​​of humic acid, fulvic acid, and humin in the control field soil were 13.02±0.98 g / kg, 2.52±0.42 g / kg, and 1.84±0.31 g / kg, respectively; while the average values ​​of the corresponding components in the experimental field were 14.10±0.97 g / kg, 3.13±0.59 g / kg, and 2.12±0.25 g / kg, respectively. It is evident that the contents of humic acid, fulvic acid, and humin in the experimental field were significantly higher than those in the control field, with average increases of 1.08 g / kg, 0.61 g / kg, and 0.28 g / kg, respectively. Figure 6 By comparing the experimental field with the control field, it can be seen that the scheme of the embodiment can achieve an overall improvement in the humus composition of the soil.

[0032] The above results indicate that the growth and reproduction of periwinkle can effectively promote the formation and accumulation of humus in paddy soil, and has a significant effect on improving soil quality.

[0033] Example 3: Comparison of changes in soil organic carbon composition between experimental and control fields During the field trial, this embodiment also monitored changes in the content of organic carbon components in paddy soil. For example... Figures 4-5 As shown, throughout the rice growing season, both the total organic carbon and dissolved organic carbon in the soil of the control field and the experimental field exhibited a dynamic trend of first increasing and then decreasing. Overall, the average total organic carbon value in the control field was 13.593±1.05 g / kg, while that in the experimental field was 14.78±1.11 g / kg. Figure 4 The average dissolved organic carbon concentrations in the control and experimental fields were 213.42 ± 45.09 mg / kg and 241.89 ± 65.24 mg / kg, respectively. Figure 5 ).

[0034] It can be seen that the total organic carbon and dissolved organic carbon contents of the experimental field soil were significantly higher than those of the control field, with average increases of 1.19 g / kg and 28.47 mg / kg, respectively. Figure 6 ).

[0035] A comparison between the experimental field and the control field shows that the proposed solution can achieve a synergistic increase in both total organic carbon and dissolved organic carbon in the soil.

Claims

1. A method for in-situ enhancement of humic components in paddy field surface soil driven by periclump organisms, characterized in that, The method includes: After crushing the rice straw, soak it in the Zhou Cong biological culture medium for a preset time. After soaking and drying the rice straw, spread it on the surface of the paddy field after rice transplanting. Adjust the field light conditions and implement periodic short-term drying management during the tillering to booting stage of rice.

2. The method according to claim 1, characterized in that, The rice straw was soaked in a cyclophosphamide culture medium for 20-30 hours.

3. The method according to claim 1, characterized in that, The pericarp culture medium is a concentrated WC culture medium.

4. The method according to claim 1, characterized in that, The soaked rice straw was naturally drained and then spread on the surface of the paddy field.

5. The method according to claim 1, characterized in that, The dried rice straw was applied on the same day after rice transplanting.

6. The method according to claim 1, characterized in that, Light and water level regulation are carried out after the application of rice straw and before rice tillering. The water level regulation includes: After spreading rice straw, maintain the first water level and gradually lower the water level to the second water level during the early stage of periclump formation and growth completion; the first water level > the second water level.

7. The method according to claim 1, characterized in that, The periodic short-term desiccation management includes: Maintain the first water level for 23-27 days, then dry it out for 3-7 days; after that, irrigate and maintain the second water level until the heading stage; the first water level > the second water level.

8. The method according to claim 6 or 7, characterized in that, The first water level is 5-7cm; the second water level is 3-5cm.

9. The method according to claim 1, characterized in that, The application rate of rice straw is 25-30 kg / mu.

10. The method according to claim 1, characterized in that, The soil humification components include humic acid, fulvic acid, and humin.

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